In power transformers, series-parallel and Delta-Y switching is done through the use of a reconnectable link board housed inside the transformer tank. This requires service personnel to open one or more manholes in the transformer cover in order to switch the transformer. Opening of the transformer at any time introduces the transformer to a number of perils, such as contamination, trapping of foreign objects in the transformer such as tools, and exposure of the operator to the transformer. It would therefore be desirable to perform such an operation by an externally operated de-energized switch that also provides positive location of the movable contacts with respect to the stationary contacts.